Mechanistic insights into Ag(+) induced size-growth from [Au(6)(DPPP)(4)](2+) to [Au(7)(DPPP)(4)](2+) clusters

The size conversion of atomically precise metal nanoclusters lays the foundation to elucidate the inherent structure–activity correlations on the nanometer scale. Herein, the mechanism of the Ag(+)-induced size growth from [Au(6)(dppp)(4)](2+) to [Au(7)(dppp)(4)](3+) (dppp is short for 1,3-bis(diphenylphosphino)propane) is studied via density functional theory (DFT) calculations. In the absence of extra Au sources, the one “Au(+)” addition was found to be regulated by the Ag(+) doping induced Au-activation, i.e., the formation of formal Au(i) blocks via the Ag(+) alloying processes. The Au(i) blocks could be extruded from the core structure in the formed Au–Ag alloy clusters, triggering a facile Au(+) migration to the Au(6) precursor to form the Au(7) product. This study sheds light on the structural and stability changes of gold nanoclusters upon the addition of Ag(+) and will hopefully benefit the development of more metal ion-induced size-conversion of metal nanoclusters.